I'm generally quite against shared libs across services for this very reason. Share patterns, sure. But code? You end up coupling services in ugly ways, because

I'm generally quite against shared libs across services for this very reason. Share patterns, sure. But code? You end up coupling services in ugly ways, because Team X has to think about how Team Y will be impacted if they need to make a change to the shared library. API clients (whatever protocol they may be using to communicate), aren't generally the hardest part of building a service. Trying to build shared ones (in my experience) is more trouble than it's worth.